Answer:
The number of liters of 25% acid solution = x = 160 liters
The number of liters of 40% acid solution = y = 80 liters
Step-by-step explanation:
Let us represent:
The number of liters of 25% acid solution = x
The number of liters of 40% acid solution = y
Our system of Equations =
x + y = 240 liters....... Equation 1
x = 240 - y
A 25% acid solution must be added to a 40% solution to get 240 liters of 30% acid solution.
25% × x + 40% × y = 240 liters × 30%
0.25x+ 0.4y = 72...... Equation 2
We substitute 240 - y for x in Equation 2
0.25(240 - y)+ 0.4y = 72
60 - 0.25y + 0.4y = 72
Collect like terms
- 0.25y + 0.4y = 72 - 60
0.15y = 12
y = 12/0.15
y = 80 Liters
Solving for x
x = 240 - y
x = 240 liters - 80 Liters
x = 160 liters
Therefore,
The number of liters of 25% acid solution = x = 160 liters
The number of liters of 40% acid solution = y = 80 liters
Well you can't actually find a number, but you can make an equation.
lets call the bag of candy x, and the number of students in the teachers class S.
she gives every student in her class 4 pieces, so to find that amount, we have to multiply the number of students in her class by 4, the pieces of candy. 4S
afterwards she has 48 pieces, which is the endpoint, x is the starting point because that's the amount of candy the teacher started with.
so your equation is x-4S=48, but the thing is, the question is looking for the amount of students she gave candy to, so we have to isolate S, or in easier words; put S on one side, and the numbers on the other.
so the equation is S=1/4x-12
Answer:
(-2,-1)
Step-by-step explanation:
y=2x+3
y=3x+5
so y=y
then:
2x+3=3x+5
3-5= 3x-2x
-2= X
x=-2
If you add the two numbers, 10 +8 is 18. The fractional parts are 1/4 and 2/4 which equals 3/4. So the total length is 18 and 3/4 feet.